Wairau Estuary

Wairau Estuary, Milford

With support from passionate locals in Milford and Castor Bay and technical advice from Auckland Council’s Healthy Waters Team, the Devonport-Takapuna Local Board has committed funding to help restore the Wairau Estuary and beach in Milford.


An estuary is a semi-enclosed body of water, which is formed when fresh water meets and mixes with the sea. Estuaries are dynamic ecosystems, which support an array of life by providing important habitat and food for many native species, including many fish, crustaceans, and birds. Estuaries also perform many important ecological functions, such as maintaining water quality in the sea by filtering sediment and excess nutrients and protecting the land by acting as buffers against tidal surges and storms.

Unfortunately, many of our estuarine environments are rapidly being degraded due to land-use changes, such as urban and industrial development, and the  Wairau Estuary in Milford is no exception. The Wairau Estuary is connected to the inland Wairau Valley Catchment, which stretches several kilometres into the industrialised and commercial heart of the Wairau Valley. Extensive environmental testing has revealed the presence of common contaminants entering the watercourse, such as heavy metals like zinc and copper, as well as bacteria, litter, and sediment. The origin of these contaminants include run-off from industrial land, high traffic roads, and recreational activities in the estuary. Despite this, at least nine native freshwater fish and crustaceans are known to inhabit this waterway.

As we continue restoring the Wairau Estuary, we will be hosting various volunteer days including planting events and litter clean ups. We would love for you to join us, and help make a meaningful contribution to the protection and conservation of your local area!

If you’d like to get involved in the restoration of the Wairau Estuary please call 0800 56 76 86 or email [email protected].